Plating barrel



April 22, 1952 F. E. NEWMAN PLATING BARREL Filed Oct. 25, 1949 a e Q .a

0 O 0 Q o o n c 0 I I I 0 a O a 0 0 I n 0 0 o 0 5 g a 0 0 0 I) 5 0 0 0 OU INVENTOR. ff/F/f/J f. A ZW/ /J/V ArromvgY Patented Apr. 22, 1952PLATING BARREL Ferris E. Newman, New Haven, Ind., assignor to UnitedStates Rubber Company, New York, N. Y., a corporation of New JerseyApplication October 25, 1949, Serial No. 123,441

9 Claims. 25989) This invention relates to plating barrels and moreparticularly to a non-metallic plating barrel which is far superior tonon-metallic plating barrels heretofore employed.

In plating small metal parts, in order to save considerable handling, ithas become customary in the art to place the parts in a perforatednonmetallic barrel for transfer through the cleaning and plating baths.Prolonged exposure to strong acid pickling solutions and to alkalicleaners at temperatures ranging as high as 200 F. places considerablestrain on the barrel. Parts of the barrel all of which must benon-metallic include a large diameter gear (usually of the order of 16in diameter), bearings and structural panels. A number of non-metallicIn the accompanying drawings:

Fig. l is a side elevation, partly broken away in section, of atypical'plating, barrel made in accordance with my invention.

Fig. 2 is a partial end view of the plating barrel shown in Fig. 1,taken on the line 22 of Fig. 1.

Fig. 3 is an enlarged section through a laminated panel which may beemployed in a modification.

In Figs. 1 and 2 of the drawings, the barrel of my invention is shown asembodying a pair of circular end members or cylinder heads I, be

tween which are arranged six foraminous panels materials have been usedfor the fabrication of rapidly disintegrates in acid. The prior artbarrels have also been subject to other disadvantages including the highcost of manufacture due to the difiiculty of working with the materialsheretofore used in construction of plating barrels. For these reasons,plating barrels heretofore available have not stood up satisfactorily inservice. For a long time workers in the art have been aware of theshortcomings of the available non-metallic plating barrels but havebeen' unable to remedy these shortcomings. V

I have now discovered that a plating barrel far superior to thoseheretofore available may .be formed from a heat-curedcomposition'comprising a cashew nut shell oil-modified phenol-aldehyderesin which is convertible under the action of heatand an intermixedhardening agent to insoluble, infusible form, a hardening agent for theresin, typically and almost invariably hexamethylenetetramine, a rubberycopolymer of butadiene and acrylonitrile, and diatomaceous earth. Theplating barrels of my invention are superior to prior plating barrels inthe following respects: hot acid resistance, hot alkali resistance,impact strength, abrasion resistance, structural strength at 200 F., andease of fabrication. As a result the plating barrels of my inventionexhibit an extremely long service life even under the most severeservice conditions and greatly reduce the cost of plating operations.

2 which have reduced end portions 3 entering corresponding recesses inthe inner faces of end members I and reduced side portions 4 which entercorresponding recesses in longitudinal rail members 5 which are ofsquare cross-section.

Rail members 5 and end members I are fixedly secured together inpermanent relationship by means of studs 6 which pass through endmembers 1 into the ends of rail members 5. The end portions 1 of railmembers 5 are reduced in size and circular in cross-section and entercorresponding circular recesses in end members I, clearance beingprovided between the ends of rail members 5 and the bottoms of thereceiving recesses in end members I so that it is possible by means ofstuds 6 to draw the shoulders ofrail members 5 into tight engagementwith end members l. The arrangement shown permits the ends I, rails 5and panels 2 to be assembled into permanent tight relationship. It willbe understood that in accordance with customary practice in the art. oneof the panels 2 is made quickly detachable for charging and dischargingthe barrel. The detachable panel 2 is not illustrated because itsconstruction is well known to the art.

Panels 2 are provided with perforations 8 which allow the cleaning andplating solutions free access into and egress from the interior of thebarrel.

The following provision is made for mounting the barrel for rotation.Coaxially with the barrel at each end thereof there is provided anannular hub 9 which is tightly secured to the adjacent end member I bymeans of studs l0. Within each of hubs 9 there is disposed a floating,freely rotatable, sleeve bearing II which freely rotatably engages hub 9and the stationary supporting sheave l2. Sheave I2 is fixedly securedtothe conventional rubber-covered metal supporting arm 13 by means ofstuds 14. It will be understood that the construction of each end-of thebarrel is identical and that each end of the barrel is supported in anidentical manner. I As is conventional, supporting arms I3 form part ofa yoke (not shown) which enables the barrel assembly to be moved easilyfrom one tank to an other. Details of the yoke are not shown because itis conventional in the plating barrel art.

The barrel of my invention is driven in the following manner:surrounding the hub 9 and mounted coaxially with the barrel at one endthereof there is provided a driving gear 15 which is fixedly secured tothe adjacent end I of the barrel by studs I 6, spacers I! serving tospace the gear a suitable distance from the end I. It will be understoodthat the gear I is driven by a stainless steel driving gear (not shown)which is conventionally provided in the assembly in which the platingbarrel is placed during operation.

In the modified form of panel 2a shown in Fig. 3, a laminated structureis employed, the major proportion of the thickness of the panelconstitilting a core 20' to which facings 2l are larninated. Preferablysuch a laminated panel is made by assembling the uncured laminae andcuring them together under heat and pressure whereby there iscoalescense at the interface. Use of a laminated structure as shown inFig. 3 enables the major portion thereof, i. e., the core 20, to beformed from the above composition with the components in proportionsimparting high strength, great stiiiness, and freedom from creep attemperatures up to 200 F., and the facings 2| to be made of the materialwith relative proportions of the three major ingredients such as toimpart high abrasion resistance.

important novel feature of the barrel of any invention is that it isconstructed throughout of theabove-mentioned heat-cured composition of acashew nut shell oil-modified phenol-aldehyde resin, a hardening agenttherefor, a rubber'y copolymer of butadiene and acrylonitrile, anddiatomaceous earth. I have found it possi-- ble to make every part ofthe barrel including not only the end members I, the panels 2 and therails 5 but also the studs 6, the hubs 9, the studs 10, the bearings H,the sheaves l2, the studs [4, the gear l5, the studs I6 and the spacersI! from such a heat-cured composition. The result is that a barrelhaving remarkably long service life is obtained. In addition, the barrelis easily manufactured because of the easy mashining properties of thecomposition.

It will be understood that with the construction shown in the drawings,the cleaning or plating liquid can pass freely through the center ofthehollow bearing collar or sheave I2 and has free access to the bearingassembly but does no harm because it can touch no exposed metal.

The floating bearing construction of my invention is highly advantageousbecause it is adapted to very long life. There is plastic-toplasticmovement in the bearing mechanism and this is much superior to a bearingin which metal is substituted for any part of the bearing structureshown. The known non-metallic plating barrels available to the artheretofore have in re cent years been provided with a floating bearingmade of nylon but such bearings are extremely the rubbery copolymer ofbutadiene and acryloto employ varying proportions of the threeingredients in constructing the various parts of the plating barrelassembly.

Thus Iprefer to form the end members i and the panels 2 or the cores ofthe panels 2a from the above composition in relative proportions of fromto of the rubbery copolymer and correspondingly from 70 to 60% of theresin, and from 30 to 40% of diatomaceous earth. Use of theseproportions gives a composition having good abrasion resistance, highmodulus, and excellent dimensional and structural stability.

I prefer to form the rails 5, hubs 9, bearings l I and sheaves l2 fromthe above composition in relative proportions of from 30 to of therubbery copolymer and correspondingly from 70 to of the resin, and from30 to 45% of di atomaceousearth. These proportions impart freedom fromcreep at elevated temperatures, good structural strength at suchtemperatures,- and also (this being important in the case of thebearings ii) good resistance to wearing upon prolongedplastio-to-plastic movement.

Where a laminated type of panel 2a is employed, I prefer to form thefacings 2! from the above composition in relative proportions of from 45to% of the rubbery copolymer and correspondingly from 55 to 40% of theresin, and from 40 to 55% of diatomaceous earth. Facings formed of sucha composition are unusually resistant to abrasion.

I prefer to form the driving gear Hi from a composition embodying from45 to 60% of the rubbery copolymer and correspondingly from 55 to 40% ofthe resin, and from 40 to 55% of diatomaeeous earth. A gear so madedisplays unusual resistance to the abrasion of the matin stainless steeldriving gear and excellent resist ance to accidental impact in movingthe barrel from tank to tank. I

v I prefer to form the studs 0', I0, l4 and I6 from the abovecomposition in relative proportions of from 35 to 40% of the rubberycopolymer and correspondingly from to 60% of the resin, and from 35 to40% of diatomaceous earth. Studs formed from these proportions areresistant to creep at elevated temperatures and strong enough to enablethe parts secured thereby to be tightly drawn together into permanentassembly and without shearing under the action of the wrench or drivingtool.

Spacers ll are preferably formed iromthe same composition as studs 6,[0, M and It.

I have found that manufactured the various parts of the plating barreland associated parts in the assembly from the various compositions justdescribed considerably enhances the life of the platingbarre1and itsutility becaus each-of the compositions described imparts particularproperties required of each of the various parts.

The composition of matter from which the parts of the plating barrel ofmy invention are.

formed, can be made by first preparing a homogeneous mixture of a cashewnut shell oil-modilied phenol aldehyde resin, a hardening agent for saidresin, particularly a methylene-yielding substance, especiallyhexa'metl'iylenetetramine, which cresols, the xylenols, etc. dricphenol, a polyhydric phenol, such as resor- ..cinol, may be used.

is capable of advancing theresin to the insoluble, infusible stage underthe action of heat, a rubbery copolymer of butadiene and acrylonitrile,viz., synthetic rubber of the type known as Buna N and as GR-A, anddiatomaceous earth. Upon shaping such a mixture to the desired form andheat-curing it, the shaping and curing typically being effected eitherby preforming the powdered mixture by pressure alone, followed bymolding of the preform under heat and pressure, or by molding of themixture directly under heat and pressure, the mixture is converted to amaterial having an unusual combination of physical properties.

Any cashew nut shell oi1-modified phenol-aldehyde resin capable of beingadvanced to insoluble, infusible form under the action of heat and ahardening agent, such as hexamethylenetetramine, may be employed in thepractice of my invention. Such resins are extremely well-known, beingavailable commercially. An example of such a resin is that known in thetrade as Durez No. 12686. Another example is Durez No. 12687 which is amixture of 92 parts of the resin sold as Durez No. 12686 and 8 parts ofhexamethylenetetramine. Still other examples of such resins containinghexamethylenetetramine as the hardening agent are the resins known inthe trade as Varcum 9820 and Varcum 9831. Such resins may be made in themanner disclosed in detail hereinafter.

As is well-known, cashew nut shell oil, which is obtained from the outershell of the cashew nut, is composed largely of anacardic acid whichupon heating is decomposed and converted to a longchain unsaturatedphenol, known as eardanol, which has a 7-tetradecenyl side-chain,

in the position meta to the hydroxyl group on the benzene ring. Whilecashew nut shell oil itself may be used as obtained from the shell, Iprefer to use the oil which has been heated to convert it to the phenoljust described by decarboxylation in the well-known manner.

The lower molecular weight phenol used in conjunction with the cashewnut shell oil in making the resin is either a monohydric or apolyhydric, preferably the former, monocyclic phenol which contains nosubstituents on the benzene ring other than hydrogen, hydroxyl groupsand lower alkyl side-chains. Examples of such lower molecular weightphenols are pheno1 itself, and

its homologues, such as ordinary cresylic acid which is a mixturecontaining the three isomeric Instead of a monohy- While the proportionof cashew nut shell oil used in making the phenolic resin may varywidely, I prefer to use it in an amount ranging from 3 to 12 mole percent based on the sum of the moles of the cashew nut shell oil and thelower "nut shell oil used in making the resin may be outside the rangegiven; thus it may range from 2 mole per cent up to 50 mole per centbased on the sum of the moles of the cashew nut shell oil and thephenol.

size.

Ordinary phenol is the preferred phenol for making the resin. Asordinary phenol is replaced by cresol, there is a tendency for the resinobtained to become softer with a consequent lowering of the hardness ofthe cured product.

The resin is typically made by heating a mix-? ture of the lowermolecular weight phenol, the cashew nut shell oil (either as such or inthe tie-,- carboxylated form) and an aldehyde, typically formaldehyde,in the presence of a suitable resinforming catalyst, usually an acid,such as an in organic acid, e. g., sulfuric or hydrochloric acid, or anacid-reacting material, as zinc chloride, to an oil-soluble stage.During the final stage of the reaction, the resin is advanced to thedesired state at which it is still convertible to insoluble, infusibleform under the action of heat and a hardening agent, and volatilematerials are removed therefrom, these objects preferably beingaccomplished simultaneously by passing superheated steam through thecharge until the residual mixture has reached the desired temperature,say 150 C. to 225 C. The residual mixture is then dumped from the kettleand allowed to cool. The cooled resin is then blended with the Buna Nand the diatomaceous earth in the manner described hereinafter. v

The resins used in accordance with the present invention arecharacterized by being completely miscible in all proportions withbutadiene acrylonitrile rubbery copolymers of relatively highaorylonitrlle content, 1. e., containing from 35 to 45%, or even more,of combined acrylonitrile. I

As the rubbery copolymer of butadiene and acrylonitrile used in thepractice of the present invention, I much prefer to employ those rubberycopolymers containing a relatively high proportion of combinedacrylonitrile, say from 35 to 45%, because these rubbery copolymers arecompletely compatible with the resin whereas rubbery copolymers or loweracrylonitrile content often tend to exhibit somewhat diminishedcompatibility resulting in somewhat poorer physical properties. Abutadiene-acrylonitrile rubbery copolymer which gives unusuallysatisfactory results in the present invention is that known commerciallyas Hycar OR-15 which contains about 42% combined acrylonitrile. Anothermaterial which gives very excellent results is that known as Perbunan 35which contains about 35% comblned acrylonitrile.

Less preferably, I may use rubbery copolymers of butadiene andacrylonitrile containing less than 35% combined acrylonitrile, say from15% up to 35%. Examples of such copolymers arethose known commerciallyas Perbunan 26 and Per bunan 18 which contain approximately 26 and 18%acrylonitrile, respectively. As the combined acrylonitrile content islowered, the compatibility with the phenolic resin tends toprogressively decrease and the physical properties of the product tendto be progressively poorer.

The third major component of the composition usedin the practice of thepresent invention is diatomaceous earth. Any of the forms of granular orpowdered diatomaceous earth commonly available commercially may beusedin the practice of my invention. Usually the diatomaceous earth has arelatively small particle Generally it is so fine that substantially allof it will pass a 100 mesh sieve. Usually the particle size of thismaterial will cover a range of from as large as 100 microns down toparticles too small to be seen. I have obtained very satisfactoryresults using the diatomaceous earth known in the tradeas Dicalite 14W,also'kno'wn asgrade L, put outby the Dicalite Company.

- In addition to the three. principal components mentioned. above, thecomposition used. in the plating barrels of my invention. also containsa hardening agent, preferably hexamethylenetetramine or its knownequivalent, in amount su'flicient to advance the resin to hard,infusible, insoluble condition during curing at elevated temperatures.Typically, the amount of hardening agent required to accomplish this isrelatively smallin proportionto the other components. Usually theproportion of this hardening agent will range from to by weight basedon. the resinv alone.

.. The composition may also contain small amounts of other suitablematerials such as mold lubricants, pigments and coloring agents to givethe-desired color, anti-oxidants for the rubber, etc. If desired,vulcanizing agents, such as sulfur, and other vulcanizing ingredients,such as the usual vulcanization accelerators and activators, may also bepresent although they are not necessary and in some cases it is believedthat slightly better results are obtained without the use of such rubbervulcanizing agents and ingredients r The. foregoing ingredients arecornmlngled tog'ether to form a uniform homogeneous mixture in anysuitable manner, typically by means of a Banbury mill or a roll mill ofthe type used for compounding rubber. The resulting mixture is sheetedout, as on a rubber calender, and is allowed to cool. It is thencomminuted, as by chopping orgrinding, to a powdered or granulatedmaterial of suitable sizev for use in making preforms or for usedirectly as a. molding powder. It is usually preferable to refrigerate.the sheeted stock to. facilitate the chopping or grinding. Typically,the stock is cooled to 35F., or below, for this purpose. A conventionalrotary knife machine may be used for grinding or chopping the mixture.

The resulting granular or powdered. material may then be preformed with.pressure but without heat to give preforms from which finished articlescan'be. molded by subjecting'the preforms to heat and pressure to givethe desired shape and cause the material to flow together and thuscoalesce to a. continuous, integral form and at the same time tionalmolding methods such as compression molding or transfer molding or bysimple placement into a mold cavity between heated platens and.subjection to an elevated temperature, say'of the order of 300 to 350F., and to pressure, say of the order of 100 to 4000 lbs. per squareinch, toform a cured sheet, slab or other article. A marked advantage ofthe mixture is that extremely high'molding pressures such as arecommonly required with the conventional phenolic molding materiar'via,pressures of the order of 8 2000 lbs. per square inch and over, are notrequired. Pressures of. the order of 200 to 150.0 lbs. per square inchare ample for molding; the material of the present invention. Anotheradvan tage is that the material cures very rapidly so that theproductivity of the molding equipment is high. I

Regardless of the method of forming or shaping the mixture, th moldingtemperatures, pressure and time should be such that the mixture flowsproperly together to give a solid, uniform,

integral molded article and that the phenolic.

resin is converted to the insoluble, infusible state. The curing timerequired may vary widely, say from ten minutes to four hours, dependingupon many factors, such as whether or not preforming was used, thethickness of the molding, etc. There seems to be no limit on curing timebe yond which the properties of the material deterl crate. There ishowever, a minimum time, namely, the time required for complete curing;at the end of this time the physical properties of the mixture havereached their maximum.

The material of the present invention can be molded to very closetolerances. This makes it possible, for example, to mold the materialdirectly into such articles as gears [5 with the teeth formed in themold and with no need for: subse-- quent machining. This i in markedcontrast to Composition A Pounds llycar OR-15 l6 Durez 12687 30 Dlcalite14W 14 Zinc stearat 0.25 Anti-oxidanL. O. 3 ax 0. 25 Iron oxide pigment3. 0

This composition when mixed and processed as described above is verysatisfactory for the con struction of end members i, panels 2, rails 5,hubs 9, bearings II, and sheaves l2.

Composition B Pounds Hycar 0R-l5. l. 10.80 Durez 12687 16.56 Dlcalite14W. 10. 00 waxwhnuw 0.2'7 Antibxldcnh. 0. 18 Iron oxide plgn1ent 3.12

This material is very satisfactory as a material from which to make endmembers I, panels 2, rails 5, hubs 9, bearings ll, sheaves l2, studs 6,

l0, l4 and i6 and spacers l1.

Composition 0. l Pounds Hycar ORl5. 24 Durcz 12687.. is Dicalite 14W LSZinc stearate. 0.3 Anti-oxidant. 0. 2i

This composition is usually suitable for the manufacture of driving gearl5 and iacings 21 of panels 2a. Where facings 2! of this composition areprovided, the core may be formed of Composition A above for goodstiffness.

This material is extremely well suited for the fabrication of gear 15.

Composition E Pounds Hycar OR-l5 Durez 12687." Dicalite 14W. Zincstearate" Anti-oxidant". Iron Oxide Pigment" Th'is'composition is verysuitable for the manufacture of rails 5, hubs 9, bearings I I, andsheaves l2.

From the foregoing description it will be seen that the presentinvention provides a plating barrel which effectively overcomes thedisadvantages of prior art non-metallic plating barrels. The barrels ofmy invention are simple and easy to construct and are rugged andlong-lived in service. They withstand the action of cleaning and platingsolutions remarkably well even at elevated temperature as high as 200F., and also resist abrasion and impact. The excellent machiningcharacteristics of the material from which they are formed and itsrelatively low cost are unusually advantageous. The plating barrels ofmy invention are highly inert chemically and electrically so that noproblem of contamination thereby is presented. Numerous other advantagesof the plating barrels of my invention will be apparent to those givenin the art.

The composition of matter described herein is disclosed and claimed inmy copending application Serial No. 98,153 filed June 9, 1949. Silentgears made of this composition are described and claimed in my copendingapplication Serial No. 98,152 filed on the same day.

Having thus described my invention what I claim and desire to protect byLetters Patent is:

1. A plating barrel comprising a pair of end members forming the ends ofthe barrel, a plurality of foraminous panels held longitudinally betweensaid end members and forming the sides of the barrel, and a plurality oflongitudinal rail members between said panels, said parts being composedof a heat-cured composition comprising a'cashew nut shell oil-modifiedphenolaldehyde resin convertible to insoluble, infusible form under theaction of heat and a hardening agent, a methylene-yielding hardeningagent for said resin, a rubbery copolymer of butadiene andacrylonitrile, and diatomaceous earth, the relative proportions being asfollows: in said end members and in at least a major proportion 'of thethickness of said panels from to 40% of said copolymer andcorrespondingly from 70 to 60% of said resin, and from 30 to 40% ofdiatomaceous earth; in said rail members from 30 to of said copolymerand correspondingly from 70 to 55% of said resin, and from 30 to 45% ofdiatomaceous earth; said percentages being by weight based on the sum ofsaid 901 51 and said resin.

2. A plating barrel comprising a pair of end members forming the ends ofthe barrel, a plurality of foraminous panels held longitudinally betweensaid end members and forming the sides of the barrel, a plurality oflongitudinal rail members between said panels, and a floating freelyrotatable sleeve bearing located at each end of the barrel coaxiallytherewith centrally of said end members, said parts being composed of aheat-cured composition comprising a cashew nut shell oil-modifiedphenol-aldehyde resin convertible to insoluble, infusible form under theaction of heat and a hardening agent, a methylene-yielding hardeningagent for said resin, a rubbery copolymer of butadiene andacrylonitrile, and diatomaceous earth, the relative proportions being asfollows: in said end members and in at least a major portion of thethickness of said panels from 30 to 40% of said copolymer andcorrespondingly from l0 to 60% of said resin, and from 30 to 40% ofdiatomaceous earth: in said rail members and in said bearings from 30 to45% of said copolymer and correspondingly from 70 to 55% of said resin,and from 30 to 45% of diatomaceous earth, said percentages being "byweight based on the sum of said copolymer and said resin.

3. A plating barrel comprising a pair of end members forming the ends ofthe barrel, a plurality of, foraminous panels held longitudinallybetween said end members and formingthe sides of the barrel, a pluralityof longitudinal rail members which with said end members support saidpanels, a floating freely rotatable sleeve bearing located at each endof the barrel co.- axially therewith centrally of said end members, anda hub located at each end of the barrel coaxially therewith centrally ofsaid end members, said hubs being fixedly connected to said end members,said bearings freely rotatably floating inside said hubs in frictionalengagement there}- with, said parts being composed of a heat-curedcomposition comprising a cashew 'nut shelljoilfmodified phenol-aldehyderesin. convertible to insoluble, infusible form under the action of heatand a hardening agent, a methylene-yielding hardening agent for saidresin, at rubbery copolymer of butadiene and acrylonitrile,anddiatomaceous earth, the relative proportions being as follows: insaid end members and in at least a major proportion of the thickness ofsaid panels from 30 to 40% of said copolymer and correspondingly from 70to 60% of said resin, and from 30 to 40% of diatomaceous earth; in saidrail members, said bearings and said hubs from 30 to 45% of saidcopolymer and correspondingly from 70 to 60% of said resin, and from 30to 45% of diatomaceous earth; said percentages being by weight based onthe sum of said copolymer and said resin. a,

4. A plating barrel comprising a pair of end members forming the ends ofthe barrel, a plurality of foraminous panels held longitudinally betweensaid end members and forming the sides of the barrel, a plurality oflongitudinal rail members between said panels, and a driving gearfixedly connected to one of said end members coaxially with the barrel,said parts being composed of a heat-cured composition comprising acashew nut shell oil-modified phenol-aldehyde resin convertible -toinsoluble, infusible form under the action of heat and a hardeningagent, a methylene-yielding hardening agent for said resin, a rubberycopolymer of butadiene and acrylonitrile, and diatomaceous earth, therelative proportions being as follows: in said end members and in atleast a major proportion of the thickness of said panels from 30 to 40%of said copolymer and correspondingly from 70 to 60% of said resinandfrom 30 to 40% of diatomaceous earth; in said rail members from 30 to45% of said copolymer and correspondingly from 70 to 55% of said resin,and from 30 to 45% of diatomaceous earth; in said gear from 45 to 60% ofsaid copolymer and correspondingly from 55 to 40% of said resin, andfrom 40 to 55% of diatomaceous earth; said percentages being by weightbased on the sum of said copolymer and said resin.

5. A plating barrel comprising a pair of end members forming the ends ofthe barrel, a plurality of foraminous panels held longitudinally betweensaid end members and forming the sides of the barrel, a plurality oflongitudinal rail members which with said end members support saidpanels, a floating freely rotatable sleeve bearing located at each endof the barrel coaxially therewith centrally of said end members, a hublocated at each end of the barrelcoaxially therewith centrally of saidend members, said hubs being fixedly connected to said end members, saidbearings freely rotatably floating inside said hubs in frictionalengagement therewith, and a driving gear fixedly connected to one ofsaid end members, said driving gear being mounted coaxially with saidbarrel and surrounding one of said hubs, said parts being composed of aheat cured composition comprising a cashew nut shell oil-modifiedphenol-aldehyde resin convertible to insoluble, infusible form under theaction of heat and a hardening agent, a methylene-yielding hardeningagent for said resin, a rubbery polymer of butadiene and acrylonitrile,atomaceous earth, the relative proportions being as" follows: in saidend members and in at least a major proportion of the thickness of saidpanels from 30- to 40% of said copolymer and correspon'dingly from '70to 60% of said resin, and from 30 to 40% of diatomaceous earth; in saidrail members, said bearings and said hubs from 30 to 45% of saidcopolymer and correspondingly from '70 to 55% of said resin, and from 30to 45% of diatomaceous earth; in said gear from 45 to 50% of saidcopolymer and correspondingly from 55 to 40% of said resin and from 40to 55% of diatomaceous earth; said percentages beingby weight based onthe sum of said copolymer and said resin.

6. A plating barrel comprising a pair of end members forming the ends ofthe barrel, a plurality of foraminous panels held longitudinally betweensaid end members and forming the sides of the barrel, a plurality oflongitudinal rail members between said panels, said rail members havingrecesses into which said panels extend, andstuds securing said railmembers to said end members, said parts being composed of a heatcuredcomposition comprising a cashew nut shell oil-modified phenol-aldehyderesin convertible to insoluble, infusible form under the action of heatand a hardening agent, a methylene-yielding hardening agent for saidresin, a rubbery copolymer of butadiene and acrylonitrile, and diatomaceous earth, the relative proportions being as follows: in said endmembers and in at least a major proportion of the thickness of saidpanels from 30 to 40% of said copolymer and correspondingly from 70 to60% of said resin and from 30 to 40% of diatomaceous earth; in

said rail members from 30 to 45% of said polymer and correspondinglyfrom 70 to 55% of said resin and from 30 to of diatomaceous earth; insaid studs from 35 to {40% of said copolymer and correspondingly from 65to 60% of said resin, and from 35 to 40% of diatomaceous earth; saidpercentages being by Weight based on the sum of said copolymer and saidresin.

7. A plating barrel comprising a pair of end members forming the ends ofthe barrel, a plurality of foraminous panels held longitudinally betweensaid end members and forming the sides of the barrel, .a plurality oflongitudinal rail members between said panels, said panels being held inrecesses in said end members and said rail members, a floating freelyrotatable sleeve bearing located at each end of the barrel coaxiallytherewith centrally of said end members, a hub located at each end ofthe barrel coaxially therewith centrally of said end members, said hubsbeing fixedly connected to said end members, said bearings freelyrotatably floatinginside said hubs in frictional engagement therewith,adriving gear mounted coaxiallywith said barrel and surrounding one ofsaid hubs, studs fixedly securing said end members to the ends of saidrail members, and studs fixedly securing said driving gear to one ofsaid end members, said parts being composed of a heat-cured compositioncomprising a cashew nut shell oil-modified phenol-aldehyde resinconvertible to insoluble, infusible form under the action of heat and ahardening agent, a methylene-yielding hardening agent for said resin, arubbery copolymer of butadiene and acrylonitrile, and diatomaceousearth, the relative proportions being as follows: in said end membersand in at least a major proportion of the thickness of said panels from30 to 40% of said copolymer and correspondingly from 70 to 60% of saidresin,.and from 30 to 40% of diatomaceous earth; in said rail menfloers,said bearings, and said hubs from 30 to 45% of said copolymer andcorrespondingly from '70 to or" said resin, and from 30 to 45% ofdiatomaceous earth; in said gear from 45 to of said copolymer andcorrespondingly from 55 to 40% of said resin and from 40 to 55% ofdiatomaceous earth; in said studs from 35 to 40% of said copolymer andcorrespondingly from to 60% of said resin and from 35 to 40% ofdiatomaceous earth; said percentages being by weight based on the sum ofsaid copolymer and said resin.

8. A plating barrel "assembly comprising a pair of end members formingthe ends of the barrel, a plurality of foraminous panels heldlongitudinally between said end members and forming the sides of thebarrel, a plurality of longitudinal rail members between said panels, ahub located at each end of the barrel coaxially therewith centrally ofsaid end members, a driving gear mounted coaxially with said barrel andsur rounding one of said hubs, a floating freely rotatable sleevebearing located at each end of the barrel coaxially therewith and insidesaid hubs, a stationary sheave located at each end of the barrelcoaxially therewith and inside said bearings, said bearings freelyrotatably floating between said hubs and said stationary sheaves and infrictional engagement with said hubs and said sheaves, studs fixedlysecuring said end members to the ends of said rail members, studsfixedly securing said hubs to said end members, and studs fixedlysecuring said driving gear to the adjacent one of said end members, saidparts being composed of a heat-cured composition comprising a cashew nutshell oil-modified phenol-aldehyde resin convertible to insoluble,infusible form under the action of heat and a hardening agent, amethylene-yielding hardening agent for said resin, a rubbery copolymerof butadiene and acrylonitrile, and diatomaceous earth, the relativeproportions being as follows: in said end members and'in at least amajor proportion of the thickness of said panels from 30 to 40% of saidcopolymer and correspondingly from 70 to 60 96 of said resin, and from30 to 40 of diatonlaceous earth, in said rail members, said hubs, saidbearings and said sheaves from 30 to 45% of said copolymer andcorrespondingly from 70 to 55% of said resin, and from 30 to 45% ofdiatomaceous earth ;'in said gear from 45 to 60% of said copolymer andcorrespondingly from 55 to 40% of said resin and from l to 55% ofdiatomaceous earth; in said studs from 35 to 40% of said copolymer andcorrespondingly from to 60% of said resin, and from 35 to 40% ofcliatomaceous earth; said percentages being by weight based on the sumof said copolymer and said resin.

REFERENCES CITED The following references are of record in the file ofthis patentL UNITED STATES PATENTS Number Name Date 478,630 Newhall etal. 1 Jul 12, 1892 690,240 Cutler Dec. 31, 1902 800,692 Thorpe Oct. 3,1905 1,934,461. Hartley Nov. 7, 1933 2,480,022 Hogaboom Aug, 23, 1949OTHER REFERENCES Shepard et a1., Modern Plastics, pages 154-156. 210,212, Oct. 1946.

